Here are the full Patch 8.15 notes (be sure to check regional editions for slight variations!):

Welcome to patch 8.15. As mentioned in previous patches, after the significant changes in midseason, we're mostly focusing on balancing outliers. As a result, this is a pretty small patch.

To start, we're taking a look at marksmen. They're still feeling some pain from their midseason changes (especially in mid-game when they can't yet afford multiple items), so we're decreasing the cost of their items to let them hit their power spike more quickly and decreasing their overall stats slightly to compensate.

Akali's rework also hits the Rift this patch, so be sure to check out her new abilities.

R - Vanguard's Edge

Recent bugfixes gave Kindred far more of a bump than expected, and as a result they have emerged as a dominant jungler. Pulling back some power and aligning their ultimate cooldown with other similarly game-changing ultimates.

E - Flay

Items

Support Items

The current cost of support items lets support players mitigate a pretty high amount of poke through potions, which makes trading feel more ineffective than we'd like.

Ancient Coin, Relic Shield & Spellthief's Edge

COST350 gold⇒400 gold

NEWTWISTED TREELINEThese changes also apply on Twisted Treeline.

Nomad's Medallion, Targon's Brace & Frostfang

TOTAL COST850 gold (unchanged)

COMBINE COST500 gold⇒450 gold

NEWTWISTED TREELINEThese changes also apply on Twisted Treeline.

Marksman Itemization

Our goal of giving marksmen a later spike was hit a little bit too hard, and it's left marksmen feeling underwhelming in the mid-game (and thus often unable to reach their late-game power). We're decreasing the cost of some marksman items so they spike earlier, but cutting some of their late-game power so they don't take over the game when they get there.

In 8.12, we made some changes to Essence Reaver that were intended to make the item more accessible, but it looks like those changes also slightly weakened the item overall. As a result, we're adding some power back.

Rapid Firecannon, Statikk Shiv & Runaan's Hurricane

Phantom Dancer

There should be clear tradeoffs in itemization; in the case of Mercurial Scimitar, the extra safety from its active does not hold an appropriate tradeoff in damage dealt.

TOTAL COST3700 gold⇒3500 gold

COMBINE COST525 gold⇒325 gold

ATTACK DAMAGE65⇒50

Jungle Items

Monster Hunter restriction now applies if the champion has the highest minion kill score, not the most gold.

The previous Monster Hunter had the effect of inhibiting the snowball of a jungle who got ahead with kills, not just a champion who was duo-farming the jungle. We're changing the mechanic to only restrict champions who have the highest minion score, not the highest gold.

REMOVEDSHARE THE LOADIf you have the most individual total gold on your team, lane minion kills will grant 10 less gold

NEWSHARE THE LOADIf you have the highest minion score on your team, lane minion kills will grant you 10 less gold

Runes

Perfect Timing

Time of activation pushed to later in the game.

In patch 8.4, we pushed the activation time of Stopwatch to 10 minutes because its prevalence in professional play was delaying or inhibiting early action. In 8.10 we tried a lower value (8 minutes), but we've begun observing the same impact on pro play, so we're reverting those changes.

ACTIVATION TIME8 minutes⇒10 minutes

Chromas Collection

Chromas are joining the Collection tab soon after 8.15 goes live! You'll be able to see all chromas you own, filter to show unowned or unavailable chromas, and group and sort your collection view just like you can with the Skins, Icons, and Wards collections.

Store, Gifting, and Forging

A few improvements to purchasing, gifting, and forging content.

WINDOW SHOPPINGIcons, wards, and chromas can now be 1-click purchased anywhere they are viewable

JUST FOR YOUGifts can be given from the friend's list

ALREADY HAVE THAT ONEEmote Permanents can now be Forged into unowned Emote Permanents

Stats

A new suite of performance-based stats for Summoner’s Rift games drop into the client during this patch.

The new Stats tab inside your profile page comes stuffed with performance-based analysis of your play across combat, map control, and income. Compare yourself to friends and enemies alike, and uncover the path to your next level of play.

NEWNEWFind the new Stats tab inside the profile page, full of data reaching back to midseason

ANALYZEMore than a dozen new stats reveal the strengths and weaknesses in your game by both position and individual champion

COMPARESet your stats against those of your friends, players of any Ranked tier, or champion-specific experts

A new Chroma collection will be heading to live! Just like the skin, ward, or icon collections, the chroma collection totals the number of chroma you own and of what tier - sortable in a variety of ways.

Akali's face in the background Surgeon Shen's splash art has been updated to go along with her champion update: